Biomolecules Question 61
Question: Chargaff’s rule is applicable to:
Options:
A) Single stranded DNA
B) Double stranded DNA
C) Single stranded RNA
D) Single stranded DNA and RNA
Show Answer
Answer:
Correct Answer: B
Solution:
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Chargaff’s rules are based on complementary base pairing between nitrogenous bases of two antiparallel strands of a double-stranded DNA molecule and thus are applicable to double-stranded DNA only.
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According to Chargaff’s rule, all cellular DNAs, regardless of the species, the number of adenosine residues is equal to the number of thymidine residues which means that A = T and the number of guanosine residues is equal to the number of cytidine residues; G = C.
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Hence, the sum of the purine residues equals the sum of the pyrimidine residues; i.e., A + G = T + C;
Final answer: Chargaff’s rule is applicable to double-stranded DNA.
BETA
